import java.util.Scanner;

public class NowCoder {
    public static String fun(String str){
        boolean flag[] = new boolean[255]; //用于存放某个字符是否出现过 默认还没有出现过
        StringBuilder stringBuilder = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            if(flag[c] == false){
                stringBuilder.append(c);
                flag[c] = true;//字符已经出现过
            }
        }
        return stringBuilder.toString();
    }
    public static void main(String[] args) {
        //输出一个字符串中的字符 多次出现的不输出 按顺序 多组输入
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNext()){
            String str = scanner.next();
            String res = fun(str);
            System.out.println(res);
        }
    }
}
